Scintillation detectors are generally used to detect radiation that is not easily detected by conventional photodetectors. A scintillator, or scintillation crystal, absorbs ionizing radiation and converts the energy of the radiation to a light pulse. The light may be converted to electrons (i.e., an electron current) with a photodetector such as a photodiode, charge coupled detector (CCD) or photomultiplier tube. Scintillation detectors may be used in various industries and applications including medical (e.g., to produce images of internal organs), geophysical (e.g., to measure radioactivity of the earth), inspection (e.g., non-destructive, non-invasive testing), research (e.g., to measure the energy of photons and particles), and health physics (e.g., to monitor radiation in the environment as it affects humans).
Scintillation detectors typically include either a single large crystal or a large number of small crystals arranged in a planar array. Many radiation scanning instruments include scintillation detectors that comprise pixellated arrays of scintillation crystals. Arrays can consist of a single row of adjoining crystal pixels (linear array) or multiple rows and columns of adjoining crystal pixels (2-D array). Linear and 2-D arrays can include thousands of crystal pixels and the system may be constructed and arranged so that an emission from each pixel can be individually detected by a photodetector.